Patent document 1: JP-A-7-301226
Patent document 2: JP-A-8-4754
Patent document 3: JP-A-11-13767
In patent documents 1 to 3, for example, sliding bearings are proposed which are each comprised of an upper casing, a lower casing, and a thrust sliding bearing piece interposed between the upper and lower casings, wherein an annular space in which the thrust sliding bearing piece is interposed is sealed by labyrinth action. In addition, Patent document 3 proposes a sliding bearing which has an annular body constituted by a plate-like ring made of a metal and disposed by being relatively slidably supported by the upper and lower casings, so as to close the outer peripheral side of the annular space between the upper and lower casings.